Gun tube support assembly

ABSTRACT

This invention relates to a gun tube support assembly ( 10 ), which comprises four support sections ( 12 ) arranged annularly around a gun tube ( 13 ) and received in an opening in a cradle ( 15 ) of a gun. Each support section ( 12 ) comprises a bush housing ( 14 ), a cradle bush ( 16 ) and a damping means sandwiched between the bush housing ( 14 ) and cradle bush ( 16 ). The damping means is in the form of a rubber pad ( 18 ) made of relatively high-temperature silicon rubber. The rubber pad ( 18 ) includes a plurality of protrusions  18.1  extending from a face of the pad ( 18 ) for abutting an outer surface of the cradle bush ( 16 ). The protrusions ( 18.1 ) accommodate compression of the pad ( 18 ), the arrangement being such that the rubber pad ( 18 ) absorbs and dampens kinetic energy emanating from the gun tube ( 13 ) during firing of a projectile.

This application is the U.S. national phase of international applicationPCT/ZA2003/000182, filed 8 Dec. 2003, which designated the U.S. andclaims priority of ZA 02/10079, filed 12 Dec. 2002, the entire contentsof each of which are hereby incorporated by reference.

INTRODUCTION AND BACKGROUND TO THE INVENTION

This invention relates to a gun tube support assembly, a cradle forcarrying a gun tube including a gun tube support assembly, and a gunprovided with a gun tube support assembly.

A conventional gun tube support assembly for a gun such as a cannon orthe like comprises a single solid metal cradle bush or a plurality ofsolid metal cradle bushes arranged annularly around a gun tube of thegun. The annularly arranged cradle bushes receive and support the guntube and the gun tube slides therein when the gun is fired.

A first disadvantage of the conventional gun tube support assembly isthat when the gun is fired, kinetic energy is transferred from aprojectile passing through the gun tube to the cannon structure via thesolid cradle bushes to cause metal fatigue and a decrease in thelifespan of the gun.

Further disadvantages of the conventional gun tube support assembly arethat the solid metal cradle bushes retains expansion and vibration ofthe gun tube and thus restrains the projectile when passing through thegun tube and causes excessive structural strains in the projectile, thushaving a negative effect on internal and external ballistics. Theprojectile is further less reliable owing to the vibrations restrainingit while passing through the gun tube.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a gun tubesupport assembly, a cradle for carrying a gun tube including a gun tubesupport assembly, and a gun provided with a gun tube support assemblywith which the aforesaid disadvantages can be overcome or at leastminimised.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a guntube support assembly comprising a plurality of support sectionsarranged annularly around a gun tube, each including:

-   -   a bush housing;    -   a cradle bush for the bush housing for receiving and supporting        the gun tube; and    -   a damping means sandwiched between the bush housing and cradle        bush, for absorbing and damping kinetic energy emanating from        the gun tube during firing thereof.

The damping means may be a resilient body selected from the groupconsisting of a rubber pad, a spring, and a pneumatic or hydrauliccushion.

Preferably the damping means comprises a pad of a relativelyhigh-temperature silicon rubber.

The rubber pad may include a plurality of protrusions extending from aface of the pad for accommodating compression of the pad.

Each bush housing may comprise a curved bush housing plate having aninner surface for abutting the resilient body.

End flanges for connecting the bush housing to a cradle of a gun may bedisposed towards opposite ends of the bush housing plate.

Removable side flanges for retaining the rubber pad may further beconnectable to the sides of the plate.

Each cradle bush may comprise a cradle bush plate curved complementaryto the bush housing plate and having an inner surface for abutting thegun tube and an outer surface for abutting the resilient body.

End flanges may extend in the direction of the bush housing from therespective opposite ends of the cradle bush plate.

The protrusions extending from the rubber pad may face towards the guntube to abut the outer surface of the cradle bush plate.

Preferably, the gun tube support assembly includes from two to six,preferably four support sections arranged annularly around the gun tubeand received in an opening in the cradle.

The cradle bush may be biased in the direction of the gun tube to keepthe cradle bush in contact with the gun tube and to allow for thermalexpansion of the gun tube.

According to a second aspect of the invention there is provided a cradlefor carrying a gun tube including a gun tube support assembly accordingto the first aspect of the invention.

According to a third aspect of the invention there is provided a gunprovided with a gun tube support assembly according to the first aspectof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described further by way of a non-limitingexample with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of an assembled gun tube support assemblyaccording to a preferred embodiment of the invention;

FIG. 2 is a perspective exploded view of a support section of the guntube support assembly of FIG. 1; and

FIG. 3 is a longitudinal-sectional view of the gun tube support assemblyof FIG. 1 surrounding a gun tube.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Referring to 1, a gun tube support assembly according to a preferredembodiment of the invention is generally designated by reference numeral10.

The gun tube support assembly 10 comprises four support sections 12arranged annularly around a gun tube 13 (shown in FIG. 3) and receivedin an opening in a cradle 15 of a gun (not shown), such as a cannon. Thesupport assembly 10 therefore supports the gun tube 13 while allowingmovement of the gun tube 13 relative to the cradle 15 when the gun isfired.

Each support section 12 comprises a bush housing 14 and a cradle bush 16for the bush housing 14, which receives and supports the gun tube 13.Each support section 12 further comprises a damping means sandwichedbetween the bush housing 14 and cradle bush 16.

The damping means is in the form of a resilient body, such as a rubberpad 18 made of relatively high-temperature silicon rubber. The rubberpad 18 includes a plurality of protrusions 18.1 extending from a face ofthe pad 18 for abutting an outer surface of the cradle bush 16. Theprotrusions 18.1 accommodate compression of the pad 18, the arrangementbeing such that the rubber pad 18 absorbs and dampens kinetic energyemanating from the gun tube 13 during firing of a projectile (notshown).

Each bush housing 14 comprises a curved bush housing plate 20 having aninner surface for abutting the rubber pad 18. End flanges 22 forconnecting the bush housing 14 to the cradle 15 of the gun, by fasteningmeans 24, are disposed towards opposite ends of the bush housing plate20. Removable side flanges 26 for retaining the rubber pad 18 is furtherconnected to the sides of the bush housing plate 20, by fastening means28.

Each cradle bush 16 comprises a cradle bush plate 30 curvedcomplementary to the bush housing plate 20 and has an inner surface thatabuts the gun tube 13 and an outer surface that abuts the rubber pad 18.End flanges 32 extend in the direction of the bush housing 14 from therespective opposite ends of the cradle bush plate 30. The cradle bush 16is made of brass to provide a smooth surface on which the gun tube 13 issupported and on which it slides, thus minimising friction.

In use, when the gun is fired and a projectile passes through the guntube 13, the latter slides in the annular support assembly 10. Expansionof the gun tube owing to internal gas pressure behind the projectile asit passes through the gun tube support assembly 10, is absorbed anddampened by the rubber pad 18.

It will be appreciated that the rubber pad 18 absorbs and dampenskinetic energy such as vibrations, and restricts it from beingtransferred from the passing projectile through to the cannon structurewhen the gun is fired. The cradle bush is biased in the direction of thegun tube to keep the cradle bush in contact with the gun tube and toallow for thermal expansion of the gun tube. Metal fatigue is thereforelimited and internal and external ballistics not as greatly affected.The applicant further foresees that less transversal forces will act onthe projectile, thus increasing its performance. It will further beappreciated that gun-jump and firing moment will be reduced through useof the gun tube support assembly 10.

It will also be appreciated that variations in detail are possible witha gun tube support assembly, a cradle for carrying a gun tube includinga gun tube support assembly, and a gun provided with a gun tube supportassembly according to the invention without departing from the scope ofthe appended claims.

1. A gun tube support assembly in which the gun tube slides when aprojectile is fired through the gun tube, the gun tube support assemblycomprising: a plurality of separable support sections that whenconnected are arranged annularly around the gun tube, each supportsection including: a bush housing; a cradle bush for the bush housingfor receiving and supporting the gun tube and on which the gun tubeslides within the gun tube support assembly when the projectile is firedthrough the gun tube; and a damping means sandwiched between the bushhousing and cradle bush, for absorbing and damping kinetic energyemanating from the gun tube during the firing of the projectile throughthe gun tube.
 2. A gun tube support assembly according to claim 1wherein the damping means is a resilient body selected from the groupconsisting of a rubber pad, a spring, and a pneumatic or hydrauliccushion.
 3. A gun tube support assembly according to claim 2 wherein thedamping means comprises a pad of a relatively high-temperature siliconrubber.
 4. A gun tube support assembly according to claim 3 wherein therubber pad includes a plurality of protrusions extending from a face ofthe pad for accommodating compression of the pad.
 5. A gun tube supportassembly according to claim 2 wherein each bush housing comprises acurved bush housing plate having an inner surface for abutting theresilient body.
 6. A gun tube support assembly according to claim 5wherein end flanges for connecting the bush housing to a cradle of a gunare disposed towards opposite ends of the bush housing plate.
 7. A guntube support assembly comprising: a plurality of support sectionsarranged annularly around a gun tube, each including: a bush housing; acradle bush for the bush housing for receiving and supporting the guntube; and a damping means sandwiched between the bush housing and cradlebush, for absorbing and damping kinetic energy emanating from the guntube during firing thereof, the damping means being a resilient bodyselected from the group consisting of a rubber pad, a spring, and apneumatic or hydraulic cushion; each bush housing comprising a curvebush housing plate having an inner surface for abutting the resilientbody; and wherein end flanges for connecting the bush housing to acradle of a gun disposed towards opposite ends of the bush housingplate; and wherein removable side flanges for retaining the resilientbody are further connectable to the sides of the bush housing plate. 8.A gun tube support assembly according to claim 7 wherein each cradlebush comprises a cradle bush plate curved complementary to the bushhousing plate and having an inner surface for abutting the gun tube andan outer surface for abutting the resilient body.
 9. A gun tube supportassembly according to claim 8 wherein the end flanges extend in thedirection of the bush housing from the respective opposite ends of thecradle bush plate.
 10. A gun tube support assembly according to claim 9wherein the protrusions extending from the rubber pad face towards thegun tube to abut the outer surface of the cradle bush plate.
 11. A guntube support assembly according to claim 1 which includes from two tosix support sections arranged annularly around the gun tube and receivedin an opening in a cradle of the gun.
 12. A gun tube support assemblyaccording to claim 1 wherein the cradle bush is biased in the directionof the gun tube to keep the cradle bush in contact with the gun tube andto allow for thermal expansion of the gun tube.
 13. A cradle forcarrying a gun tube including a gun tube support assembly according toclaim
 1. 14. A gun provided with a gun tube support assembly accordingto claim 1.